package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author amanda
 * @Description 唯一的ID
 */
@Component
public class RedisIdWorker {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    // 开始时间戳
    private static final long BEGIN_TIMESTAMP = 1577836800;
    // 序列号位数
    private static final long COUNT_BITS = 32;
    public Long nextId(String keyPrefix) {
        // 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond-BEGIN_TIMESTAMP;
        // 生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long increment = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        // 拼接并返回
        return timestamp << COUNT_BITS | increment ;
    }

//    public static void main(String[] args) {
//        LocalDateTime time = LocalDateTime.of(2020, 1, 1, 0, 0, 0);
//        long second = time.toEpochSecond(ZoneOffset.UTC);
//        System.out.println("second = " + second);
//    }
}
